Carnac's Folly by Gilbert Parker, Fiction, Action & Adventure (Paperback)

"Oh, look," said Junia. "Look -- Carnac!" She pointed in dismay.

Carnac turned to see Denzil, and he saw a portion of the bank of the river disappear with him. He looked down -- in another moment he had made his way to the river's edge. The girl remained at the top. The boy said to her: "You stay there. I'll tell you what to do."

"Is -- is he killed?" she called with emotion.

"Killed! No," he called back to her. "I can see him move. Don't be frightened. He's not in the water. It was only about a thirty-foot fall. You stay there, and I'll tell you what to do."

But that was just the beginning.